Motor operator for circuit breaker



Oct. 2l, 1969 H, R SHAFFER ET AL 3,474,363

MOTOR OPERATOR FOR CIRCUT BREAKER Filed Aug. 21, 1967 4 Sheets-Sheet 1Oct. 21, 1969 H, R, SHAFFER ET AL 3,474,363

MOTOR OPERATOR FOR CIRCUIT BREAKER Oct. 21, 1969 H, R SHAFFER ET AL3,474,363

v MOTOR OPERATOR FOR CIRCUIT BREAKER Filed Aug. 21, 1967 4 Sheets-Sheet5 defi/eff mv P.E.v 5- n ef/#5 arf 0F; 5 f6 /Te//fp 4f Ff-'5.5. /f/f?Pd/Efe Magri INVENTORS /Mw ef//ffff Oct. 21, 1969 H. R SHAFFER ET AL3,474,363

MOTOR OPERATOR FOR CIRCUIT BREAKER United States Patent O 3,474,363MOTOR OPERATOR FOR CIRCUIT BREAKER Howard R. Shaffer, Glenside, and.lohn C. Brumeld, Philadelphia, Pa., assignors, by mesne assignments, toI-T-E Imperial Corporation, Philadelphia, Pa., a corporation of DelawareFiled Aug. 21, 1967, Ser. No. 662,160 Int. Cl. Htllh 3/42 U.S. Cl.335-73 8 Claims ABSTRACT OF THE DISCLOSURE A uni-directional motorhaving a rotatable shaft; a cam attached to and radially spaced from theshaft; an arm pivotally mounted on a support and having cam followersthereto attached; as the cam rotates it engages either one or the otherof the cam followers; in engaging the first of the cam followers, itmoves the pivotally mounted arm clockwise and in engaging the other ofthe cam followers, it moves the pivotally mounted arm counterclockwise;a circuit breaker handle being connected with the pivotally mounted armand being movable by the arm between its on and off and between the tripand off positions as the arm pivots; a cam operated switch mechanism foractuating the motor for rotation; a remote control switch device foractuating the motor; and an automatic reset switch for permitting themotor to operate to cause reclosing of the circuit breaker from the tripposition.

This invention relates to a motor operated circuit breaker mechanismand, more particularly, to a means for connecting a uni-directionalmotor to a circuit breaker for remote operation of the circuit breaker,wherein the operating handle of the circuit breaker can be freelymanually operated without interference from the motor or the meansconnecting the motor to the circuit breaker.

A circuit breaker is usually operable by a handle which is manuallymovable between two extreme positions, a circuit breaker on and oposition. The breaker has an automatic tripping mechanism and when thecircuit breaker is automatically tripped, the operating handleautomatically moves to an intermediate trip position. To reclose thebreaker, its handle must be moved rst to the olf position to reset thecircuit breaker operating mechanism and then to the on positioncompleting circuit breaker reclosing. For an example of a circuitbreaker of this type, see U.S. Patent No. 2,996,589, issued on Aug. 15,1961, to Felix Myers, entitled Pivoted Bimetal and assigned to theassignee of the instant invention.

In order to operate a circuit breaker from a remote position, it iscommon practice to mount adjacent a circuit breaker a motor having anoperating mechanism which is connected to the circuit breaker operatinghandle. Both uni-directional and reversible direction motors have beenemployed for this purpose. Uni-directional motors are preferred becauseof their simplicity. However, in the prior art, uni-directional motorshave required elaborate clutch mechanisms to permit manual operation ofthe circuit breaker without interference with the movement of the handleby the operating mechanism. A person manually operating a prior artcircuit breaker must exert a force to overcome both the biasing forceexerted by the circuit breaker mechanism itself and the resistance ofthe clutch mechanism to movement. In addition, the motor used inconjunction with the remotely operable circuit breaker must be stronger,and thus more expensive, to overcome the drag exerted by the clutchmechanism. Prior art devices have also required elaborate brakemechanisms to prevent over-travel of the mech- 3,474,363 Patented Oct.21, 1969 anism moving the circuit breaker handle, thereby to preventunnecessary stresses from being applied repeatedly to the handle whichcauses premature breakdown of the circuit breaker.

A reversible direction motor arrangement is costly and still requiresclutch and brake mechanisms.

Examples of prior art arrangements are found in U.S. Patent Nos.2,864,912, 2,864,911, 2,870,288, 2,912,046, 2,354,135, and 2,228,466.

The present invention overcomes the drawbacks of the prior art byproviding a motor operable from a remote point, which motor isuni-directional and is connected to the circuit breaker operating handleby a mechanism which precludes the necessity for providing either aclutch mechanism for permitting manual operation of the handle itself,or a braking mechanism to prevent over-travel. Additional advantagesobtained from the mechanism of the present invention are that the unitis free to be operated manually at all times and that the position ofthe circuit breaker handle does not interfere with proper motoroperation. An over-travel device is provided to protect the circuitbreaker operating handle from unnecessary stresses due to over-travel ofthe breaker handle operating mechanism. The over-travel protectionprecludes the mounting dimensions from being critical, which savesconsiderable time in positioning of the mechanism of the instantinvention with respect to a circuit breaker.

The present invention employs a pivotally mounted arm having one end inengagement with the manually operable handle of the circuit breaker.

On the other side of the pivot of the arm is positioned two camfollowers, which are engaged one at a time, by a cam to be described.The cam moves the rst cam follower to pivot the arm clockwise and movesthe other cam follower to pivot the arm counterclockwise. Movement ofthe arm in one direction moves the breaker handle to the on position andmovement of the arm in the other direction moves the breaker handle tothe olf position.

To prevent any harm from befalling the circuit breaker operating handledue to over-travel of the cam followers and, hence, of the portion ofthe arm in engagement with the operating handle, the pivotally mountedarm is comprised of two elements, pivoted at the pivot of the arm, andeach of which holds one of the cam followers. Each element terminates ina prong. The prong of one element is positioned on one side of thehandle and the prong of the other element is positioned on the otherside of the handle, whereby as the handle is moved in a direction onlyone of the prongs is exerting a force on it.

The two elements of the arm are joined by a spring or other biasingmeans which can be compressed but is biased to a stretched condition.The cam followers and prongs are arranged so that when the cam followeron one of the elements is being engaged by the cam to pivot the arm, theprong on the other element engages the breaker handle. If the cam causesone cam follower to overtravel in one direction, the handle stops at theend point of its movement, halting the prong on the one element, whichprong was causing the handle to move, and thus halting that element. Theover-traveling cam follow and arm element, in continuing to travel,compresses the spring. Hence, the spring or biasing means absorbs theforce of over-travel and the handle is not unduly stressed.

A uni-directional motor is provided having a drive shaft to which ismounted a cam disc. A substantial segment of the cam disc, approximatinga semi-circle, is part of a circular disc having a first diameter andthe remaining segment of the cam disc is formed from a circle having asecond diameter, greater than the rst diameter. The disc has theretosecured a cam for engaging each of the cam followers. As the disc isrotated, the cam engages one or the other of the cam followers to pivotthe arm either clockwise or counterclockwise.

The cam is positioned on the cam disc such that when the motor is notoperating the cam is spaced away from both of the cam followers, wherebythe circuit breaker operating handle may be operated manually withoutthe cam, the motor or the remotely controllable mechanism interferingwith the operation of the handle.

Positioned adjacent the cam disc is a switch, which is moved between twopositions by the edge of the two radii cam disc. The switch isconnectable in series with the motor for causing the same to rotate tocause movement of the operating handle.

A remote control device electrically connectable in series with the camswitch and Awith the motor is provided. The remote control switch may bemoved between an on and an olf position, at both of which positions themotor is caused to operate to move the operating handle of the circuitbreaker, respectively to the circuit breaker on or off positions.

In lone embodiment, the remote control switch is a maintained contactswitch, such as a toggle type switch, with the movable switch armremaining in constant contact with one or the other of the switch on oroff contacts.

Another embodiment of remote control switch is comprised of a momentarycontact switch having two movable bridging contacts one of which, whenmoved to a closed position, completes the on circuit in the remotecontrol switch; and the other of which, when moved to a closed position,completes the off circuit in the remote control switch. Both bridgingcontacts are normally open.

An automatic reset switch may be provided for automatically returningthe operating handle to the reset position after the circuit breaker hasbeen tripped and the operating handle has been moved to the tripposition by a fault current passing through the circuit being protected.The automatic reset switch is connectable in series with the motor forcausing the same to be activated. 'Ihe reset switch is positioned andadapted to be moved by the pivotable arm, whereby when the pivotable armis moved to the trip position by movement of the operating handle, thereset switch is operated to cause automatic reset.

With a maintained contact control switch, in the event the circuitbreaker is tripped, and an automatic reset switch has been provided, andthe remote control switch remains at the on position, the cam is rotatedrst to move the arm and hence the operating handle to the oi positionwhich resets the circuit breaker mechanism and then to move the arm, andhence, the operating handle, to the on position, which recloses thecircuit breaker contacts. If the remote control switch is in the offposition, the cam is rotated only to move the arm and the operatinghandle to the oit position, which resets the circuit breaker mechanismand may be called the reset position.

With a momentary contact remote control switch which remains open at theon and olf positions until manually operated, the cam is rotated to movethe arm, and hence the operating handle, to the reset position, whichrelatches the circuit breaker mechanism. The remote control switch mustbe manually operated to complete the on circuit for the cam to rotatethe arm and the operating handle to the on position, which closes thecircuit breaker contacts.

Accordingly, it is a primary object of the present invention to providea remotely controllable motor operated mechanism for operating a circuitbreaker.

It is another object of the present invention to provide such amechanism which employs a uni-directional motor.

It is another object of the present invention to provide such amechanism which permits manual operation of the operating handle of thecircuit lbreaker without intertference by the remotely controllablemechanism.

It is a further object of the present invention to eliminate thenecessity for a complicated clutch mechanism for permitting manualoperation of the circuit breaker operating handle.

It is another object of the present invention to provide such amechanism which employs a cam device to operate upon a pivotally mountedarm which, in turn, operates upon the operating handle of the circuitbreaker.

These and other objects of the present invention Will become apparentafter a reading of the following description of the accompanyingdrawings in which:

FIG. 1 is a plan view of the mechanism of the present invention showinga circuit breaker operating handle in the off or reset position;

FIG. 2 is a view in the direction of FIG. 1 showing the mechanism of thepresent invention when the operating handle is in the on position, andshowing, in phantom lines, the position of the pivotally mounted arm ofthe mechanism of the instant invention when the circuit breaker handleis in the tripped position;

FIG. 3 is a view in the direction 3 3 of FIG. 2 showing the pivotallymounted arm of the mechanism of the instant invention and itsinteraction with the circuit breaker handle, the reset switch and thecam on the cam disc;

FIG. 4 is a View in the direction 4 4 of FIG. 1;

FIG. 5 schematically illustrates the electric circuitry of the remotelyoperable mechanism of the instant invention when the mechanism is atrest in the oit position of FIG. 1 and when the remote control switchhas maintained contacts;

FIG. 6 schematically illustrates the circuitry of the remotely operablemechanism of FIG. 5 at, and shortly after, it is in the position of FIG.1 and while it is moving toward the on position of FIG. 2

FIG. 7 schematically illustrates the circuitry of the mechanism of FIG.5 when the mechanism is at rest in the on condition of FIG. 2 and, inphantom, illustrates the circuitry shortly after it has been moved tocause the return of the mechanism to the off position;

FIG. 8 schematically illustrates the circuitry of the mechanism of FIG.5 immediately after the circuit breaker has been tripped, as illustratedin phantom in FIG. 2, and shows the circuitry during the entire resetoperation until the mechanism reaches the static condition of FIGS. 2and 7, in the on position; and

FIG. 9 schematically illustrates the electric circuitry of the remotelyoperable mechanism of the instant invention, including a momentarycontact remote control switch, after the breaker has been tripped.

Referring to the figures, and particularly to FIG. l, a circuit breaker10 is provided having an operating handle 11 which protrudes through thecasing of the breaker 10. The handle is movable through slot 12, bymeans exterior to the breaker 10, between an olf and an on position,where the circuit breaker contacts are, respectively, disengaged orengaged within the circuit breaker. The interior mechanism of such acircuit breaker is well known in the art and is not here shown. For anexample of a circuit breaker interior having an operating handle 11, seeU.S. Patent No. 2,996,589. In the event that the circuit breakercontacts are tripped apart due to a fault current passing through thecircuit being protected, the operating handle 11 moves to anintermediate trip position, shown in phantom in FIG. 2, between the onand the oit position. To reclose the circuit breaker in order that itmight again respond to a fault current through the circuit beingprotected, the :operating handle 11 must be moved by a means exterior tothe circuit breaker 10, iirst to the olf position, which relatches thecircuit breaker trip mechanism, and the-n to the on position, whichreengages the circuit breaker contacts. The present invention relates toa mechanism for remotely controlling the operation of the circuitbreaker operating handle from the on to the o position, or vice versa,and from the trip position to the oi position.

The mechanism 20 comprises a support 21 for all of the elements of themechanism, including the motor described below. An arm 22 is pivotallymounted on pivot 23 to support 21. The arm has a means comprising prongs24, 24a, which form a notch, for engaging the operating handle 11 of thecircuit breaker.

To the arm 22 are attached two cam followers 26 and 27 for being engagedby the hereinbelow described cam 41. The cam followers 26 and 27, as canbe seen in FIG. 3, extend toward the support 21, thereby to enable thecam 41 to engage them. The cam followers 26 and 27 are so positionedthat when cam follower 27 is engaged and force is applied to it by cam41, the arm 22 is pivoted clockwise about pivot 23, thereby causingprong 24a to move handle 11 toward the on position. The manner ofoperation will be described in greater detail below. As will becomeapparent, cam followers 26, 27 are so positioned that no matter whatposition they are placed in, proper operation of the instant inventionwill occur.

Arm 22 may be comprised of separate elements 23 and 29, both of whichelements are pivoted at pivot 23. The separate elements are provided toprevent damage to the circuit breaker 1t) due to over-travel in eitherdirection of the arm 22 as a result of its being operated by the motor,in a manner described below. Cam follower 27 is attached to element 28and cam follower 26 is attached to element 29.

Prong 24 is an integral part of element 28 and prong 24a is an integralpart of element 29. A biasing means, such as spring 30, joins theelements 28 and 29 to absorb the stresses of over-travel. Spring 30 isadapted to be loaded by being compressed. Operation of the over-travelprotection means will be considered below.

A unidirectional motor M, not shown in FIG. 1, but

vschematically shown in FIGS. 5-8, is supported from support 21. Themotor is of a type well known in the art which is activated by anelectric power source. Upon being activated, the motor drive shaft 32 iscaused to rotate unidirectionally clockwise, as viewed in FIGS. 1 and 2.Attached to the motor drive shaft 32 and supported above the mechanismhousing 21 is a cam disc 34 which is rotatable clockwise by theoperating shaft 32 of the motor.

Adjacent the edge of the cam disc 34 is positioned a movable switch arm36 which has a roller 37 that rolls along the edge of the cam disc 34.The switch arm 36 is movable between two positions by cam disc 34, aswill be described.

Cam disc 34 is comprised of two segments of a circle each having adifferent radius. When segment 3S, having a smaller radius, is adjacentroller 3'7 (FIG. l), switch arm 36 is in a first or cam off position andwhen segment 39, having a larger radius, is in engagement with roller 37(FIG. 2), switch arm 36 is in a second or cam on position. While disc 34is shown as being comprised of two segments, the disc may be comprisedof a greater plurality of segments, alternate ones of which would have agreater or lesser radius. The speed of rotation of disc 34 would beappropriately adjusted to permit operation, as described below, of themechanism of the present invention.

Connected with lthe cam disc 34 is cam 41 which is comprised, in theillustrated embodiment, of a projection xedly attached to the cam disc34 at approximately the center of the arc of the greater radius segment39 of cam disc 34. Referring to FIGS. 3 and 4, cam 41 is sufficientlyshort to avoid its contacting elements 28 or 29 of arm 22. However, itis tall enough to engage cam followers 26 and 27 which project towardcam disc 34. As cam 41 rotates clockwise due to rotation of disc 34, itengages and either slides or rolls along either cam follower 27 or camfollower 26. The cam followers each have a curved end portion 42 offwhich the cam 41 slides when it reaches the end of the cam follower. Thecam followers 26, 27 are of a sufficient length toward their ends 42that cam 41 presses on each of them for a sucient period that the arm 22is enabled to move the operating handle either to the on or to the offposition. The length of cam followers 26, 27 is predetermined and endportions 42 are so positioned that cam 41 will not drive the camfollowers and, hence, the arm 22 an excessive distance in eitherdirection, which would apply excessive pressure on the operating handle11 and would cause premature breakage of the circuit breaker or of itscasing.

A remote control switch 43 of a single-pole, doublethrow type, `wellknown in the art, is provided which is connected to the motor, in amanner to be described in conjunction with FIG. 5, for causing the motorto rotate shaft 32, thereby to cause movement of the operating handle 11to either of the on or off positions. Switch 43 has maintained contacts.In another form of the invention, to be described in conjunction withFIG. 9, a remote control switch `61 is shown having momentary engagementcontacts.

An automatic reset switch 4S also of a single-pole, double throw type,well known in the art, may be provided if it is desired to have themechanism Ztl, which uses a remote control switch with maintainedcontacts, reset the circuit lbreaker It? in the on position after thebreaker has tripped as a result of a fault current passing through thecircuit being protected. The reset switch has a switch arm 46 movablebetween two positions. An operating member 47 is provided for engagementwith arm 22. As can be seen in FIGS. 1 and 4, when the circuit breakeroperating handle 11 is in the off position, arm 22 is out of engagementwith operating lever 47. Referring to FIGS. 2 and 3, when the circuitbreaker operating handle is in the on position (as shown in solid linein FIG. 2), arm 22 is in engagement with lever 47. lf the circuitbreaker operating handle is moved to the trip position, shown in phantomin FIG. 2, arm 22 is out of engagement with operating lever 47.Referring to FIG. 3, when arm 22 is in engagement with operating lever47, operating lever 47 is depressed and switch arm 46 is moved to a rstposition. Referring to FIG. 4, when arm 22 is out of engagement `withoperating lever 47, lever 47 is no longer depressed, thereby permittingswitch 45 to be in a second position, giving rise to results describedbelow.

Refer to FIG. 5 which schematically illustrates the electricalinterconnection of the various components of the mechanism of thepresent invention. The power source leads to the remote control switch43, which has a switch arm 51 that is operable between two positions.When switch arm 51 lcloses the connection between the power source andcontact 52, a signal is sent, as described below, to move the operatinghandle to the off position of FIG. 1. When switch arm 51 is moved toconnect the power source to contact 53, a signal is given to move theoperating handle 11 to the on position of FIG. 2, as described below.

Contacts 52 and 53 of the remote control switch are, respectively,connected with contacts 54 and 55 of the cam operated switch 35. Whenthe lesser radius segment 38 of cam disc 34 is adjacent roller 37, asshown in FIG. 1, switch arm 36 is in the cam off position and connectsthe motor M to contact 5S within switch 35. When the greater radiussegment 39 of disc 34 engages roller 37, switch arm 36 is moved to itscam on position and the motor is connected with contact 54.

If it is desired to provide automatic reset of the circuit breaker to onwhen it has tripped, reset switch 45 is provided. The power source isconnected to reset switch arm 46 which is movable between contacts 56and 57. Arm 46 is in engagement with contact 57 when the breaker is inthe on position as shown in solid line in FIG. 2 and in FIG. 3. Arm 46engages contact 56 when the breaker is moved to the off position ofFIGS. l and 4 or the tripped position shown in phantom in FIG. 2. Inthese positions, the arm 22 (FIGS. 1 and 2) is out of engagement withswitch lever 47.

Operation of the mechanism of the instant invention will now bedescribed. Referring to FIGURES 1 and 5, the mechanism of the instantinvention is shown in a static condition where the circuit breakeroperating handle is in the off position. Note that the remote controlswitch arm 51 is in engagement with contact 52 which indicates that theperson operating the remote control switch desires that the circuitbreaker operating handle 11 bein the oif position. In FIGURE l, theroller 37 is adjacent the smaller radius segment 38 of cam disc 34 and,therefore, in FIGURE 5, the switch arm 36 is in engagement with contact55 of switch 35. Accordingly, there is no complete circuit joining thepower source and the motor M, whereby the motor does not operate.

Referring to FIGURES 1 and 6, the operator of the remote control switch43 now desires that the circuit breaker operating handle 11 be movedfrom the olf to the on position. He moves the remote control switch arm51 so that it closes a circuit through contact 53. Motor M is now in acomplete circuit with the power source and it begins to rotate disc 34.Referring to FIG- URE 1, as disc 34 rotates clockwise, cam 41 engagescam follower 27 and -continued rotation of disc 34 causes cam 41 to bearupon cam follower 27, pivoting arm 22 about pivot 23, thereby movinghandle 11 toward the on position. Just as handle 11 arrives at the onposition, cam 41 slides free of end 42 of cam follower 27 (see FIGURE 2)and arm 22 ceases to be pivoted clockwise by cam 41. The operatinghandle 11 is now in the on position.

Referring to FIGURES 2 and 7, immediately after cam 41 separates fromcam follower 27, greater radius segment 39 of disc 34 contacts roller 37and arm 36 of cam switch 35 moves to the cam on position in contact withcontact 54. The completed circuit between the motor M and the powersource is Ibroken and the motor stops, thereby halting the rotation ofdisc 34 and cam 31 Referring to FIGURE 7, when it is desired to returnthe handle 11 to the off position of FIGURE 1 from the on position ofFIGURE 2, remote control switch arm 51 is moved, as shown in phantom inFIGURE 7, into engagement with contact 52 to the on position. Motor M isagain in a complete cir-cuit with the power source and begins to rotate.Cam 41 engages cam follower 26 and as cam 41 rotates, it causes arm 22to pivot counterclockwise to the olf position of FIGURE 1. Just as arm22 reaches its position of FIGURE 1, cam 41 separates from cam follower26 and arm 22 halts. The greater radius segment 39 of disc 34 moves outof engagement with roller 37 of switch 35 and lesser radius segment 38moves adjacent roller 37, whereby switch 35 moves from the cam onposition with arm 36 in contact with contact 54, as shown in FIGURE 7,to the cam off position with arm 36 in contact with contact 55, as shownin FIGURE 5. Motor M is disconnected from the power source and halts sothat handle 11 remains stationary in the off position.

The reset switch 45 plays no role in the remotely controlled movement ofhandle 11 between the off and the on positions. Accordingly, ifautomatic reset of the contacts after tripping of the circuit breaker isnot desired, the reset switch may be eliminated.

It is assumed that automatic reset of the circuit breaker is desired. Aswas noted above, in FIGURES 2 and 7, the circuit breaker handle 11 isshown in a static condition, with the motor M being electricallydisconnected, and the operating handle 11 being in the on position. Notethat the contact arm 46 of the reset switch 45 engages contact 57 and isin the breaker on position. Note further that the remote control switcharm 51 is in contact with contact 53 and that the remote control switchoperator desires that the circuit breaker remain in the on position.

Assume that a fault current has been detected by the circuit breaker,that the cooperating contacts of the circuit breaker have been trippedapart, and that the operating handle 11 of the circuit breaker has beenmoved to its intermediate or tripped position shown in phantom in FIGURE2. Note in the phantom lines in FIGURE 2, that the arm 22 has beenmoved, due to the tripping movement of handle 11, from being inengagement with lever 47 of switch 45 to being out of engagement withlever 47. As shown by a comparison of FIGURES 7 and 8, the movement ofarm 22 from its solid to its phantom line position in FIGURE 2 hascaused switch arm 46 of reset switch 45 to be moved from being inengagement with contact 57, in the breaker on position, to being inengagement with contact 56 in the breaker off or breaker trippedposition. With the reset switch 45 being in the condition shown inFIGURE 8, a circuit is completed between the power source and the motorM. Included in the circuit is the power source, switch arrn 46, contact56, contact 54, switch arm 36 and motor M.

Referring to FIGURE 2, as motor M is actuated, disc 34 begins to rotateclockwise and cam 41 thereto secured engages cam follower 26, whichurges arm 22 counterclockwise, which, in turn, moves operating handle 11to the oit position shown in FIGURE 1. As shown in FIG- URE 1, as soonas arm 22 has moved handle 11 to the olf position, cam 41 rotates freeof end 42 of cam follower 26 and arm 22 no longer applies force tooperating handle 11. At the same time, switch arm 36 moves from the camon position of FIGURES 2 and 8, where it is in engagement with contact54, to the cam olf position of FIGURES 1 and 6, where it is inengagement with contact 55.

The remote control switch has never been moved by the operator from theon to the off position, whereby remote control switch arm 51 is inengagement with contact 53. Accordingly, when cam 41 releases camfollower 26, the electric circuitry of the mechanism 20 is in thecondition shown in FIGURE 6. The motor M is still in a complete circuitwith the power source and disc 34 continued to rotate. Operating handle11 is then moved to the on position of FIG. 2 as has been fullydescribed above in connection with FIGS. 2, 6 and 7.

If, on the other hand, the operator has moved remote control switch 43to the off position, where switch arm 51 is in engagement with contact52, as shown in dotted lines in FIG. 6, once disc 34 has rotated to itsposition of FIG. 1, switch 35 is in the cam off position and the motor Mis no longer in a complete circuit with the power source, whereby thearm 22 and handle 11 stay at the olf or breaker reset position.

Referring to FIG. 9, identical elements to those shown in FIGS. 5-8 areidentically numbered. The mechanism 20a diiers from mechanism 20 ofFIGS. 5-8 in that the maintained contact remote control switch 43 isreplaced with momentary contact switch 61. Switch 61 has bridgingcontacts 62 and 63 which are normally in the open position as shown inFIG. 9, and which may be biased open but which are manually operableclosed to close their respective contacts 64 and 65, closing,respectively, the circuits to contacts 54 and 55 of cam switch 35.Contacts 62, 63 may be replaced with a single bridging contact (n-otshown) intermediate switch contacts 64, 65 which is movable intoengagement with either of these contacts, but is biased away from both.When one or the other of contacts 62, 63 is held manually closed, itoperates in the same fashion as Contact arm 51 when it is in engagement,respectively, with one of contacts 52, 53 in FIGS. 5-8.

If automatic reset of the circuit breaker is desired but with thecircuit breaker remaining in the o position instead of returning to theon position as described above, it is best to employ the remote controlswitch 61 of the momentary contact type. The normal resting position ofswitch 61 would have both contacts 64, 65

t aims.

disengaged. Therefore, a fault current tripping the circuit breakercauses switch arm 46 of switch 4S to engage contact 56 and the motor isenergized through contact 54 and switch arm 36. As the motor operatesthe circuit breaker to its off position and switch 35 is operated to thecam o position by cam 34, switch arm 36 disengages from contact 54 andengages Contact 55, electrically disconnecting the motor M from thepower source since switch arms 62, -63 of switch `61 are not inengagement with either of contacts 64, 65, Therefore, the breakermechanism is reset and the breaker remains in the off position until theremote control switch operator moves switch contact 63 to engage contact65 to turn the circuit breaker to the on position.

By the simple mechanism shown in FIG. 1, therefore, a uni-directionalmotor may be used with a remote control device for operating a circuitbreaker `to move the operating handle of the circuit breaker and hencethe circuit breaker mechanism itself, t-o any of the circuit breakeroperating positions.

As noted above, arm 22 is comprised of elements 2S and 29, which arejoined at pivot 23 and by biasing means or spring 30, to prevent damageto the circuit breaker 19 and to the circuit breaker handle 11 byover-travel of the arm 22. If the breaker and mechanism 20 are properlypositioned with respect to each other cam 41 should rotate free of camfollowers 26, 27 just as the handle 11 has reached its extremepositions. But if the breaker 1t? and mechanism 20 are not positionedexactly, as is diliicult in the field, or if the cam 41 is not releasedat the proper moment, there will be over-travel of arm 22.

The over-travel device of the invention operates as follows. lf camfollower 26 attached to element 29 of Cam 22, is pivoted too farcounterclockwise by cam 41, prong 24 on element 28 is prevented bybreaker handle 11 from pivoting, and the relative movement of element 29with respect to element 28 is absorbed by compression of spring 30,without undue stress being applied to handle 11.

Similarly, if cam 41 pivots cam follower 27 on element 28 too farclockwise, pr-ong 24a on element 29 is prevented from pivoting too farby handle 11 and the relative movement between elements 28 and 29 isabsorbed by compression of spring 30, without undue stress being appliedto handle 11.

For a further important feature of the present invention, refer to FIGS.1 and 2, and note that when operating handle 11 and mechanism 20 are ina static condition, in either the off or the on positions of the circuitbreaker, the cam 41 is out of engagement with both of the cam followers26 and 27. If instead of operating the circuit breaker handle 11 from aremote point, it is desired to manually operate handle 11, the handle 11may be manually operated to any of its positions without having cam 41or any other structrue interfere with the movement of operating handle11 and arm 22. Thus, when operating handle 11 is operated, it is notnecessary to overcome any obstructive forces exerted by the motor M. Nocomplicated clutch mechanism is required, as in the prior art, to permitthe circuit breaker handle 11 to be manually operated withoutinterference from the motor. Thus greater simplicity in manufacture canbe achieved. Furthermore, the manual operator of the handle 11 need notexert an excessive force to overcome both the natural resistance tooperation of the circuit breaker handle 11 and the resistance of thecomplex clutch mechanism to movement.

Although there has been described a preferred embodiment of this novelinvention, many variations and Inodifications will now lbe apparent tothose skilled in the art. Therefore, this invention is to be limited,not by the specilic disclosure herein, but only by the appending Theembodiments of the invention in which an excluve privilege or propertyis claimed are defined as follows:

` 1. In an operator for a circuit breaker, said circuit breaker lhavingan operating handle,

said operator comprising,

an arm lhaving engaging means for engaging said operating handle;

a support; a pivot on said support; said arm being pivotally mounted onsaid pivot, whereby said arm is pivotable to operate the handle of thebreaker;

a motor means for rotating a cam support in a first direction;

a cam support connected to said motor means;

a cam mounted on said cam support for being rotated and for engaging camfollowers;

the improvement comprising,

said arm comprising a first and second element;

said rst and said second elements being connected together by a biasingmeans;

said engaging means on said arm comprising,

said first arm element having thereto attached a first prong means forengaging one side of said operating handle and said second elementhaving thereto attached a second prong means for engaging the other sideof said operating handle;

a rst cam follower connected to said first element and a second camfollower connected to said second element;

one of said cam followers being positioned to be engaged by said cam assaid cam rotates, such that said arm is pivoted in one direction to movesaid handle to a first position, and the other of said cam followersbeing positioned to be engaged by said cam as said cam rotates, suchthat said arm is pivoted in the opposite direction to move said handleto a second position;

actuating means connected with said motor means for actuating said motormeans to rotate said cam, thereby to pivot said arm; means fordeactuating said motor means when said handle reaches either of saidfirst and said second positions;

said cam followers being so positioned that when said first cam followeris being engaged by said cam, said second prong means is engaging thecircuit breaker operating handle; and when said second cam follower isbeing engaged by said cam, said first prong means is engaging thecircuit breaker operating handle.

2. In an operator for a circuit breaker, said circuit breaker Ihaving anoperating handle,

said operator comprising,

an arm having engaging means for engaging said operating handle;

a support; a pivot on said support; said arm being pivotally mounted onsai-d pivot, whereby said arm is pivotable to operate the handle of thebreaker;

a motor means for rotating a cam support in a first direction;

a cam support connected to said motor means;

a cam mounted on said cam support for being rotated and for engaging camfollowers;

the improvement comprising,

a first and a second cam follower connected to said arm;

one of said carn followers being positioned to be engaged by said cam assaid cam rotates, such that said arm is pivoted in one ldirection tomove said handle to a first position, and the other of said camfollowers being positioned to be engaged by said cam as said camrotates, such ythat said arm is pivoted 1n the opposite direction tomove said handle to a second position;

actuating means connected with said motor means for actuating said motormeans to rotate said cam, thereby to pivot said arm; means fordeactuating said motor means when said handle reaches either of saidfirst and said second positions;

sai-d first cam follower being so shaped and of such a length that saidcam ceases to engage said first cam follower when said operating handlehas been moved into said first position;

and said second cam follower is so shaped and of such a length that saidcam ceases to engage said second cam follower when said operating handlehas been moved into said second position;

whereby said handle of the circuit breaker is manually operable withoutinterference from said cam and said motor means.

3. In the operator of claim 2, the improvement further comprising,

said arm comprising a first and second element; said first and saidsecond elements being connected together by a biasing means;

said first cam follower being connected to said 1irst element and saidsecond carn follower being connected to said second element;

said first arm element having thereto attached a first prong means forengaging one side of said operating handle and said second elementhaving thereto attached a second prong means for engaging the other sideof said operating handle;

said cam followers being so positioned that when said first cam followeris being engaged by said cam, said second prong means is engaging thecircuit breaker operating handle and when said second cam follower isbeing engaged by said cam, said first prong means is engaging thecircuit breaker operating handle.

4. In an operator for a circuit breaker, said circuit breaker having anoperating handle,

said operator comprising,

an arm having engaging means for engaging said operating handle;

a support; a pivot on said support; said arm being pivotally mounted onsaid pivot, whereby said arm is pivotable to operate the handle of thebreaker;

a motor means for rotating a cam support in a first direction;

a cam support connected to said motor means;

a cam mounted on said cam support for being rotated and for engaging camfollowers;

the improvement comprising,

a first and a second cam follower connected to said arm;

one of said cam followers being positioned to be engaged by said cam assaid cam rotates, such that said arm is pivoted in one direction to movesaid handle to a first position, and the other of said cam followersbeing positioned to be engaged by said cam as said cam rotates, suchthat said arm is pivoted in the op- .posite direction to move saidhandle to a second position;

actuating means connected with said motor means for actuating said motormeans to rotate said cam, thereby to pivot said arm; means fordeactuating said motor means when said handle reaches either of saidfirst and said second positions;

said cam support having thereto connected first and second switchengaging means which are moved past a first switch as said cam supportrotates;

said means for actuating said motor means comprising,

a first switch for being engaged by said first and said second switchengaging means; said first switch being operable to a third positionwhen engaging said first switch engaging means and being operable to afourth position when engaging said second switch engaging means; saidfirst switch being connected to said motor means, on the one hand;

a remote control device having a first and a second contact; said firstswitch being connected with said first contact of said remote controldevice when said first switch is in said third position, therebyconnecting said motor means with said first contact of said remotecontrol device, and being connected to said second contact of saidremote control device when said first switch is in said fourth position,thereby connecting said motor means With said second contact of saidremote control device;

a power source connected to said remote control device and to said motormeans;

said remote control device being operable to a fifth position wherein-said power source is connected to said first contact thereof and to asixth position wherein said power source is connected to said secondcontact thereof;

a reset switch connected to said remote control device and beingoperable to a seventh position, where said reset switch breaks a circuitin which it is positioned, and to an eighth position, where said resetswitch is connected to said first switch when said first switch is insaid third position;

means for actuating said reset switch connected with said arm; said armbeing movable by the circuit breaker handle to a trip position,intermediate said first and said second positions of said handle, whenthe circuit breaker trips; said reset switch actuating means on said armoperating said reset switch to its said eighth position when said arm ismoved by said handle into said trip position.

5. In the operator for a circuit breaker of claim 4, the

improvement further comprises,

said cam support comprises a cam disc and said first and said secondswitch engaging means comprise, respectively, a first segment of saiddisc having an edge at a first radius of said disc, and a second segmentof said disc having an edge at a second radius of said disc; said secondradius being greater than said first radius;

said cam disc being rotatable past said first switch,

6. In the operator for a circuit breaker of claim 4, the

improvement further comprises,

said first cam follower being so shaped and of such a length that saidcam ceases to engage said first cam follower when said operating handleis in said first position;

and said second cam follower being so shaped and of such a length thatsaid cam ceases to engage said second cam follower when said operatinghandle is in said second position;

whereby the handle of the circuit breaker is manually operable withoutinterference from said cam and said motor means.

7. In the operator for a circuit breaker of claim 6, the

improvement further comprises,

said first element having thereto attached a first prong means forengaging one side of said operating handle and said second elementhaving thereto attached a second prong means for engaging the other sideof said operating handle;

said cam followers being so positioned that when said first cam followeris being engaged by said cam, said second prongy means is engaging thecircuit breaker operating handle and when said second cam follower isbeing engaged by said cam, said first prong means is engaging thecircuit breaker operating handle.

8. In an operator for a circuit breaker, said circuit breaker having anoperating handle, said operator comprisin g,

a fourth means connected to said motor means for engaging said secondand third means; v

one of said second and third means bein-g positioned to be engaged bysaid fourth means, whereby said fourth means is adapted to move the oneof said second and third means in a first direction such that said armis pivoted so that said handle is operated to said first position andthe other of said second and third means being positioned to be engagedby said fourth means, whereby said fourth means is adapted to move theother of said second and third means in a second direction such thatsaid arm is pivoted so that said handle is operated to said secondposition;

the improvement comprising,

actuating means connected with said motor means for actuating said motormeans, whereby Said fourth means is moved to operate said handle to saidfirst and said second position;

means for deactuating said motor means when said handle reaches eitherof said first and said second positions;

said fourth means having thereto attached a first and a second switchengaging means;

a first switch for being engaged by said first and said second switchengaging means; said first switch being movable to a third position whenengaging said first switch engaging means and being movable to a fourthposition when engaging said second switch engaging means; said firstswitch being connected to said motor means;

a remote control device having a first and a second contact; said firstswitch being connected with said first contact of said remote controldevice when said first switch is in said third position, therebyconnecting said motor means with said rst contact of said remote controldevice, and being connected to said second contact of said remotecontrol device when said first switch is in said fourth position therebyconnecting said motor means with said second contact of said remotecontrol device;

a power source connected to said remote control device and to said motormeans;

said remote control device being operable to a fifth position whereinsaid power source is connected to said first contact thereof and to asixth position wherein said power source is connected to said secondcontact thereof;

a reset switch connected to said remote control device and being movableto a seventh position where said reset switch breaks a circuit in whichit is positioned and to an eighth position, where said reset Switch isconnected to said first switch when said first switch is in said thirdposition;

means for actuating said reset switch connected with said arm; said armbeing movable by the circuit breaker handle to a trip position,intermediate Said first and said second positions of said handle, whenthe circuit breaker trips; said reset switch actuating means operatingsaid reset switch to its said eighth position when said arm is moved bysaid handle into said trip position.

References Cited UNITED STATES PATENTS 3,213,235 10/1965 SOOS 335-743,213,236 10/1965 Pendy 335-74 3,332,044 7/1967 Camp 335-73 BERNARD A.GILHEANY, Primary Examiner H. BROOME, Assistant Examiner

